The technology exists for tracking items on a fairly granular scale. It is done in the pharmaceutical industry, it is done with eggs.

It is also done in food through fair-trade, organic and other certifications.

Why can't we scale this up - cost or lack of will power?

If we had to do it for everything wouldn't the cost of the technology come down? With the pervasiveness of mobile phones globally (see the maternal health challenge) we should be able to implement global systems that even include small farmers.